Finding the Fourth Proportional to 12,986.64, 17,917.37 and 7,945.61

Step by Step Solution

1. Step 1: Write the proportion equation
   12,986.64 : 17,917.37 = 7,945.61 : x
2. Step 2: Convert to fraction form
   12,986.64/17,917.37 = 7,945.61/x
3. Step 3: Cross multiply
   12,986.64x = 17,917.37 × 7,945.61
4. Step 4: Simplify right side
   12,986.64x = 142,364,304.93
5. Step 5: Solve for x
   x = 142,364,304.93/12,986.64
6. Step 6: Final answer
   x = 10,962.37